Before Apollo 8, the furthest anyone had been from Earth was about 850 miles (1600 km). Apollo 8 increased that distance to nearly a quarter of a million miles. Its three crew members were the first human beings to fly to the moon, or to anywhere beyond low Earth orbit.

This mission also marked the first time that anyone rode atop a Saturn V, the enormous multi-stage rocket built specifically to propel crewed spacecraft to the moon. The Saturn V was as high as a 36-story building, more powerful than 85 Hoover Dams, and consisted of three million parts which all had to function reliably. There had been only two test launches of this massive vehicle, the most recent of which -- the unmanned Apollo 6 mission four months earlier -- had suffered several major malfunctions.

But Apollo 8 went up without a hitch. The crew members, Commander Frank Borman, Command Module Pilot James A. Lovell, Jr., and William A. Anders (designated as Lunar Module Pilot even though the mission did not carry an actual lunar module), rode to the moon inside a capsule essentially identical to the one that would carry the Apollo 11 astronauts the following year on their way to the first lunar landing. In place of a lunar module, which was not yet ready to be tested in a lunar mission, it carried an equivalent amount of mass.

Air Force General Samuel C. Phillips directed the Apollo program at the time. Reflecting upon this historic flight, he wrote, "In Mission Control early in the morning of December 24 the big center screen, which had carried an illuminated Mercator projection of the Earth for the past three and one-half years -- a moving blip always indicated the spacecraft's position -- underwent a dramatic change. The Earth disappeared, and upon the screen was flashed a scarred and pockmarked map with such labels as Mare Tranquillitatis, Mare Crisium, and many craters with such names as Tsiolkovsky, Grimaldi, and Gilbert. The effect was electrifying, symbolic evidence that man had reached the vicinity of the moon."

The astronauts began orbiting the moon on 24 December 1968 and became the first humans to see firsthand the mysterious far side, the face of the moon which always points away from Earth. Science fiction writer Arthur C. Clarke later wrote that the crew told him they had been tempted to radio back the sighting of a giant black monolith, as seen in the movie Clarke wrote with Stanley Kubrick, 2001: A Space Odyssey. "Alas," he wrote, "discretion prevailed."

Over the course of 10 orbits lasting 20 hours, the astronauts took photographs for both operational and scientific purposes, described lunar topography to Mission Control as an aid to planning the upcoming lunar-surface missions, and beamed television pictures of the moon and of the Earth as seen from lunar orbit.

During a broadcast on Christmas Eve, they read aloud the Biblical account of creation from the book of Genesis. Then on Christmas day, they fired the service module engine to break free of lunar orbit and return to Earth.

They splashed down in the Pacific Ocean before dawn on 27 December, about 1,000 miles (1,600 km) SSW of Hawaii and less than three miles (5 km) from the recovery ship, USS Yorktown.

As General Phillips described the results of the mission, "Not only was the technology of going to the moon brilliantly proven; men began to view the Earth as 'small and blue and beautiful in that eternal silence,' as Archibald MacLeish put it, and to realize as never before that their planet was worth working to save. The concept that Earth was itself a kind of spacecraft needing attention to its habitability spread more widely than ever."

The Apollo 8 Command Module is on display at the Chicago Museum of Science and Industry, Chicago, Illinois.